Tensions were building in the St. Louis suburb of Ferguson, Missouri, on Monday as the community girded for a decision by a grand jury over whether to indict the white police officer who fatally shot an unarmed black teen in August.

The shooting sparked weeks of unrest and ongoing demonstrations, and some groups have threatened widespread protests if Ferguson police officer Darren Wilson is not charged with a crime in the death of Michael Brown, 18.

St. Louis County Prosecuting Attorney Robert McCulloch, addressing speculation about the timing of an announcement, said on Monday his expectation a grand jury decision would not be reached until mid-to-late November had not changed.

The prosecutor’s office will advise the public when a determination is made and claims of an announcement date or time from other sources “are rank speculation and should be ignored,” McCulloch said in a statement.

There is widespread expectation the grand jury will not indict Wilson. Some businesses have boarded up windows and made plans for how to protect themselves and their property if protests ignite into violence and destruction.

Shortly after Wilson killed Brown on Aug. 9, there was looting and vandalism of Ferguson businesses, as protesters clashed with police. The protests over Brown’s death have since been mostly peaceful as the grand jury decision is awaited.

Tory Russell, a co-founder of Hands Up United, said the group protesting Brown’s death had been hoping to negotiate terms of engagement with law enforcement authorities that might help keep demonstrations peaceful but that such talks had gone nowhere.

“I told them if there is no indictment, please only come through neighborhoods when called. Please do not continue to traumatize our community,” said Russell. But “they don’t want to meet with the youth. I honestly believe they are planning to kill us in the streets.”

Dee Butler, office manager for an area chiropractor, said her business was planning to pack up patient records and take them home on Friday, which is the day many people think a grand jury decision could be announced.

“We are hoping it’s not going to be as bad as people say it’s going to be. It looks like there will be protests, but we don’t expect violence,” she said.